The present invention relates to devices and methods which can be used to alter an eating behavior of a subject.
During the past 20 years, obesity among adults has risen significantly in the United States. The latest data from the National Center for Health Statistics show that 30 percent of U.S. adults 20 years of age and older—over 60 million people—are obese. Obesity requires long-term management; the goal of treatment is weight loss to improve, prevent occurrence of, or eliminate related health problems.
Numerous approaches for the treatment of obesity are known in the art, including drug treatment, surgical procedures and implantable devices.
Drugs for treatment of obesity fall into three general categories, appetite altering drugs such as dexfenfluramine or sibutramine which suppresses appetite by altering neurotransmitter release or uptake in the brain; metabolism-changing drugs such as Orlistat which prevents the action of lipases (enzymes that break down fat) produced in the pancreas; and drugs that increase energy output (‘thermogenic’ drugs) such as ephedrine and caffeine which stimulate weight loss by reducing appetite and perhaps by stimulating the body to produce more heat.
Although these drugs offer useful therapeutic effects, there remains a need for more effective obesity treatment drugs. Such a need will fuel tremendous commercial opportunity and so in the future drugs which target gastrointestinal or brain receptors for satiety, or block/mimic the action of satiety altering hormones and substances (such as ghrelin, CCK, PYY, obestatin, leptin, glucagons, neuropeptide Y and the like) might make their way to the market.
Two forms of surgery have been recommended by government consensus panels that can be performed to treat severe obesity. Both are for people with severe cases of obesity, over 100 lbs above ideal body weight (e.g., BMI>40 kg/m2), who have not had effective weight loss with diet, exercise or drugs.
Gastroplasty involves surgically reducing the size of the stomach, thus limiting food intake. Vertical band gastroplasty (VBG) is successful in more than 85% of patients, and weight loss is maintained over prolonged time periods (Barclay Obes Surg. 2004 November-December; 14(10):1415-8). Gastric bypass surgery (e.g. Roux en Y) creates a small stomach pouch and connects this pouch to the second portion of the intestines. Gastric bypass surgery can initially result in substantial weight loss, and approximately 80 percent of patients remain at least 10 percent below their preoperative body weight for 10 years after surgery. The efficacy of the procedure is probably due to the increased sense of fullness with a reduced gastric volume and the symptoms of “dumping” associated with the passage of gastric contents into the intestines, which act as deterrents to eating (Rosenbaum et al. Obesity NEJM Volume 337:396-407 Aug. 7, 1997 Number 6). Although gastric bypass surgery is highly effective, it carries a risk of morbidly and it is more extensive and difficult to perform than gastroplasty.
Numerous devices for altering satiety are also known in the art. Some devices restrict stomach size or food intake via bands [e.g. lap band et al. MJA 2005; 183 (6): 310-314] or space occupying elements [e.g. intra-stomach balloons—Obes Surg. 2005 September; 15(8):1161-4]. Others alter stomach or pyloric muscle activity via neuronal or muscular implanted electrodes (Shikora, Journal of gastrointestinal surgery Volume 8, Issue 4, Pages 408-412; Xu et al. Gastroenterology 2005; 128:43-50).
Although numerous treatment approaches are available at present, the most effective approach with the best long term effects is restricted to the treatment of severely obese people and in addition it requires complicated surgery which can lead to severe complications or death.
There is thus a widely recognized need for, and it would be highly advantageous to have, an eating behavior altering device and method devoid of the above limitations.